• Video
  • Shop
  • Culture
  • Family
  • Wellness
  • Food
  • Living
  • Style
  • Travel
  • News
  • Book Club
  • Newsletter
  • Privacy Policy
  • Your US State Privacy Rights
  • Children's Online Privacy Policy
  • Interest-Based Ads
  • Terms of Use
  • Do Not Sell My Info
  • Contact Us
  • © 2026 ABC News
  • News

Just Say No ... or Else You Get Cancer?

ByRADHA CHITALEABC News Medical Unit
February 06, 2009, 9:52 PM

Feb. 9, 2009 — -- Internet photos of swimming phenomenon Michael Phelps, 23, possibly indulging in an Olympian lungful of marijuana smoke scandalized many and may have caused him to lose face and the faith of some of his fans -- not to mention a lucrative sponsorship from Kellogg.

But according to new research, if Phelps makes a habit of smoking up, he could stand to loose more than a fan base.

For the first time, researchers have linked frequent marijuana use to an increased risk of testicular cancer, according to an article published today in the journal Cancer.

"There's been very little research done on marijuana use and its association with cancer risk," said Janet Daling, the senior author of the article and an epidemiologist and member of the Public Health Sciences Division at the Fred Hutchinson Cancer Research Center (FHCRC) in Seattle. "This is the first time this association has been shown."

Using a population-based, case-control study, Daling surveyed 369 men diagnosed with testicular cancer and 979 healthy men between ages 18-44 about their history with marijuana use.

After controlling for family history and lifestyle factors, including alcohol and tobacco use, which could also be associated with testicular cancer, the researchers found that being a marijuana smoker was associated with a 70 percent increased risk of testicular cancer.

Participants who used marijuana once a week or more or who had long-term exposure to marijuana since adolescence were at twice the risk for testicular cancer than those who never used marijuana.

In addition, the association between frequent marijuana use and testicular cancer was more pronounced among men who had nonseminomas, a more aggressive form of testicular cancer, than those who had seminomas. Nonseminomas also tend to strike in younger men.

Get Your Health and Wellness Questions Answered at the ABCNews.com OnCall+ Wellness Center

Although this research has the most implications for habitual users, it goes against commonly held beliefs that marijuana is one of the more benign recreational drugs, a potential concern given the number of people who have tried marijuana in their lives.

Up Next in News—

Artemis II astronauts on their out-of-this-world mission: 'Adventure of a lifetime'

April 30, 2026

'Rogue' AI agent went haywire at tech company. The CEO is still 'bullish' on the technology

April 29, 2026

King Charles III gives toast at White House state dinner: Read his full speech

April 29, 2026

This San Francisco shop is run completely by an AI agent

April 23, 2026

Shop GMA Favorites

ABC will receive a commission for purchases made through these links.

Sponsored Content by Taboola

The latest lifestyle and entertainment news and inspiration for how to live your best life - all from Good Morning America.
  • Contests
  • Terms of Use
  • Privacy Policy
  • Do Not Sell My Info
  • Children’s Online Privacy Policy
  • Advertise with us
  • Your US State Privacy Rights
  • Interest-Based Ads
  • About Nielsen Measurement
  • Press
  • Feedback
  • Shop FAQs
  • ABC News
  • ABC
  • All Videos
  • All Topics
  • Sitemap

© 2026 ABC News
  • Privacy Policy— 
  • Your US State Privacy Rights— 
  • Children's Online Privacy Policy— 
  • Interest-Based Ads— 
  • Terms of Use— 
  • Do Not Sell My Info— 
  • Contact Us— 

© 2026 ABC News